The present invention relates to a battery and a related method and, more particularly, to a battery and a related method using a flat type battery with a structure wherein an outer sheath material is formed of a composite laminate film made of polymer-metal to allow circumferences thereof to be joined to one another by thermal welding for thereby accommodating and sealing an electric power generating component composed of a positive electrode plate, a separator and a negative electrode plate
Recently, electric vehicles powered by electric power outputs of drive sources and hybrid cars powered by engines and motors in combination attract public attention, and a development work has taken up an important weight in an industrial field to provide a battery with a high energy density and high power output for these applications.
The batteries for these applications include a structure wherein a wound electric power generating component is accommodated in a cylindrical case and a structure wherein the wound electric power generating component or an electric power generating component composed of a stack of flat-plate shaped electrodes and separators is accommodated in a flat case.
Further, Japanese Patent Application Laid-Open Publication No. 11-224652 discloses a battery wherein an outer sheath is made of a laminate film whose circumference is sealed by thermal welding to provide a hermetically sealed structure.
Furthermore, Japanese Patent Application Laid-Open Publication No. 2000-133218 discloses a structure wherein at least either one of electrode terminal leads includes a lead wire which is preliminarily covered with resin to provide an improved sealing property.